* 26 guns from 4- to 10-pounders
** 8 guns from 2- to 16-pounders
This tabulation reflects contemporary conditions quite clearly. The
most serious invasions of Spanish Florida took place during the first
half of the eighteenth century, precisely the time when the Castillo
armament was strongest. While most of the guns were in battery
condition, the table does have some pieces rated only fair and may
also include a few unserviceables. Colonial isolation meant that
ordnance often served longer than the normal 1,200-round life of an
iron piece. A usual failure was the development of cracks around the
vent or in the bore. Sometimes a muzzle blew off. The worst casualties
of the 1702 siege came from the bursting of an iron 16-pounder which
killed four and seriously wounded six men. At that period,
incidentally, culverins were the only guns with the range to reach the
harbor bar some 3,000 yards away.
Although when the Spanish left Florida to Britain in 1763 they took
serviceable cannon with them, two guns at Castillo de San Marcos
National Monument today appear to be seventeenth century Spanish
pieces. Most of the 24- and 32-pounder garrison cannon, however, are
English-founded, after the Armstrong specifications of the 1730's, and
were part of the British armament during the 1760's. Amidst the
general confusion and shipping troubles that attended the British
evacuation in 1784, some ordnance seems to have been left behind, to
remain part of the defenses until the cession to the United States in
1821.
The Castillo also has some interesting United States guns, including a
pair of early 24-pounder iron field howitzers (c. 1777-1812). During
the 1840's the United States modernized Castillo defenses by
constructing a water battery in the moat behind the sea wall. Many of
the guns for that battery are extant, including 8-inch Columbiads,
32-pounder cannon, 8-inch seacoast and garrison howitzers. St.
Augustine's Plaza even boasts a converted 32-pounder rifle.
[Illustration: Figure 29--VAUBAN'S MARINE CARRIAGE (c. 1700).]
Garrison and ship carriages were far different from field, siege, and
howitzer mounts, while mortar beds were in a separate class entirely.
Basic proportions for the carriage were obtained by measuring (1) the
distance from trunnion to base ring of the gun, (2) the diameter of
the base ring, and (3) the diameter of the second reinforce ring. The
result was a quadrilateral figure that served as a key in laying out
the carriage to fit the gun. Cheeks, or side pieces, of the carriage
were a caliber in thickness, so the bigger the gun, the more massive
the mount.
A 24-pounder cheek would be made of timber about 6 inches thick. The
Spaniards often used mahogany. At Jamestown, in the early 1600's,
Capt. John Smith reported the mounting of seven "great pieces of
ordnance upon new carriages of cedar," and the French colonials also
used this material. British specifications in the mid-eighteenth
century called for cheeks and transoms of dry elm, which was very
pliable and not likely to split; but some carriages were made of young
oak, and oak was standard for United States garrison carriages until
it was replaced by wrought-iron after the Civil War.
For a four-wheeled English carriage of 1750, height of the cheek was
4-2/3 diameters of the shot, unless some change in height had to be
made to fit a gun port or embrasure. To prevent cannon from pushing
shutters open when the ship rolled in a storm, lower tier carriages
let the muzzle of the gun, when fully elevated, butt against the sill
over the gun port.
On the eighteenth century Spanish garrison carriage (fig. 28), no
bolts were threaded; all were held either by a key run through a slot
in the foot of the bolt, or by bradding the foot over a decorative
washer. Compared with American mounts of the same type (figs. 30 and
31), the Spanish carriage was considerably more complicated, due
partly to the greater amount of decorative ironwork and partly to the
design of the wooden parts which, with their carefully worked
mortises, required a craftsman's skill. The cheek of the Spanish
carriage was a single great plank. English and American construction
called for a built-up cheek of several planks, cleverly jogged or
mortised together to prevent starting under the strain of firing.
[Illustration: Figure 30--ENGLISH GARRISON CARRIAGE (1756). By
substituting wooden wheels for the cast-iron ones, this carriage
became a standard naval gun carriage.]
Müller furnished specifications for building truck (four-wheeled)
carriages for 3- to 42-pounders. Aboard ship, of course, the truck
carriage was standard for almost everything except the little swivel
guns and the mortars.
Carriage trucks (wheels), unless they were made of cast iron, had iron
thimbles or bushings driven into the hole of the hub, and to save the
wood of the axletree, the spindle on which the wheel revolved was
partly protected by metal. The British put copper on the _bottom_ of
the spindle; Spanish and French designers put copper on the _top_,
then set iron "axletree bars" into the bottom. These bars strengthened
the axletree and resisted wear at the spindle.
A 24-pounder fore truck was 18 inches in diameter. Rear trucks were 16
inches. The difference in size compensated for the slope in the gun
platform or deck--a slope which helped to check recoil. Aboard ship,
where recoil space was limited, the "kick" of the gun was checked by a
heavy rope called a breeching, shackled to the side of the vessel
(see fig. 11). Ship carriages of the two-or four-wheel type (fig. 31),
were used through the War between the States, and there was no great
change until the advent of automatic recoil mechanisms made a
stationary mount possible.
[Illustration: Figure 31--U. S. NAVAL TRUCK CARRIAGE (1866).]
With garrison carriages, however, changes came much earlier. In 1743,
Fort William on the Georgia coast had a pair of 18-pounders mounted
upon "curious moving Platforms" which were probably similar to the
traversing platforms standardized by Gribeauval in the latter part of
the century. United States forts of the early 1800's used casemate and
barbette carriages (fig. 10) of the Gribeauval type, and the
traversing platforms of these mounts made training (aiming the gun
right or left) comparatively easy.
Training the old truck carriage had been heavy work for the
handspikemen, who also helped to elevate or depress the gun. Maximum
elevation or depression was about 15° each way--about the same as
naval guns used during the Civil War. If one quoin was not enough to
secure proper depression, a block or a second quoin was placed below
the first. But before the gunner depressed a smoothbore below zero
elevation, he had to put either a wad or a grommet over the ball to
keep it from rolling out.
Ship and garrison cannon were not moved around on their carriages. If
the gun had to be taken any distance, it was dismounted and chained
under a sling wagon or on a "block carriage," the big wheels of which
easily rolled over difficult terrain. It was not hard to dismount a
gun: the keys locking the cap squares were removed, and then the gin
was rigged and the gun hoisted clear of the carriage.
A typical garrison or ship cannon could fire any kind of projectile,
but solid shot, hot shot, bombs, grape, and canister were in widest
use. These guns were flat trajectory weapons, with a point-blank range
of about 300 yards. They were effective--that is, fairly accurate--up
to about half a mile, although the maximum range of guns like the
Columbiad of the nineteenth century, when elevation was not restricted
by gun port confines, approached the 4-mile range claimed by the
Spanish for the sixteenth century culverin. The following ranges of
United States ordnance in the 1800's are not far different from
comparable guns of earlier date.
_Ranges of United States smoothbore garrison guns of 1861_